MAX148/MAX149 19-0464 Rev 4 1/10 +2.7V to +5.25V, Low-Power, 8-Channel, Serial 10-Bit ADCs General Description Features The MAX148/MAX149 10-bit data-acquisition systems S 8-Channel Single-Ended or 4-Channel Differential combine an 8-channel multiplexer, high-bandwidth Inputs track/hold, and serial interface with high conversion S Single-Supply Operation: +2.7V to +5.25V speed and low power consumption. They operate from a S Internal 2.5V Reference (MAX149) single +2.7V to +5.25V supply, and sample to 133ksps. S Low Power: 1.2mA (133ksps, 3V Supply) Both devices analog inputs are software configurable for unipolar/bipolar and single-ended/differential operation. 54A (1ksps, 3V Supply) The 4-wire serial interface connects directly to SPIK/ 1A (Power-Down Mode) QSPIK and MICROWIREK devices without external S SPI/QSPI/MICROWIRE/TMS320-Compatible 4-Wire logic. A serial-strobe output allows direct connection to Serial Interface TMS320-family digital signal processors. The MAX148/ S Software-Configurable Unipolar or Bipolar Inputs MAX149 use either the internal clock or an external seri- al-interface clock to perform successive-approximation S 20-Pin DIP/SSOP Packages analog-to-digital conversions. The MAX149 has an internal 2.5V reference, while the Ordering Information MAX148 requires an external reference. Both parts PIN- INL have a reference-buffer amplifier with a Q1.5% voltage- PART TEMP RANGE PACKAGE (LSB) adjustment range. MAX148ACPP 0C to +70C 20 Plastic DIP 1/2 These devices provide a hard-wired SHDN pin and MAX148BCPP 0C to +70C 20 Plastic DIP 1 a software-selectable power-down, and can be pro- grammed to automatically shut down at the end of a MAX148ACAP 0C to +70C 20 SSOP 1/2 conversion. Accessing the serial interface automatically MAX148BCAP 0C to +70C 20 SSOP 1 powers up the MAX148/MAX149, and the quick turn-on Ordering Information continued at end of data sheet. time allows them to be shut down between all conver- Contact factory for availability of alternate surface-mount sions. This technique can cut supply current to under package. Specify lead-free by placing + by the part number 60FA at reduced sampling rates. when ordering. The MAX148/MAX149 are available in a 20-pin DIP and *Contact factory for availability of CERDIP package, and for a 20-pin SSOP. processing to MIL-STD-883B. Not available in lead-free. For 4-channel versions of these devices, see the MAX1248/MAX1249 data sheet. Typical Operating Circuit +3V Applications V DD CH0 V DD Portable Data Logging 0.1FF O TO DGND +2.5V Data Acquisition ANALOG INPUTS MAX149 Medical Instruments AGND CH7 Battery-Powered Instruments CPU COM VREF Pen Digitizers 4.7FF CS I/O Process Control SCLK SCK (SK) DIN MOSI (SO) READJ DOUT MISO (SI) 0.01FF SSTRB Pin Configuration appears at end of data sheet. V SS SHDN SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.+2.7V to +5.25V, Low-Power, 8-Channel, Serial 10-Bit ADCs ABSOLUTE MAXIMUM RATINGS V to AGND, DGND ..............................................-0.3V to +6V SSOP (derate 8.00mW/NC above +70NC) ....................640mW DD AGND to DGND ...................................................-0.3V to +0.3V CERDIP (derate 11.11mW/NC above +70NC) ..............889mW CH0CH7, COM to AGND, DGND ........... -0.3V to (V + 0.3V) Operating Temperature Ranges DD MAX148 C P/MAX149 C P .............................. 0NC to +70NC VREF, REFADJ to AGND ...........................-0.3V to (V + 0.3V) DD MAX148 E P/MAX149 E P ............................ -40NC to +85NC Digital Inputs to DGND ...........................................-0.3V to +6V MAX148 MJP/MAX149 MJP ........................ -55NC to +125NC Digital Outputs to DGND .......................... -0.3V to (V + 0.3V) DD MAX149BMAP ............................................... -55NC to +125NC Digital Output Sink Current ................................................25mA Storage Temperature Range ............................ -60NC to +150NC Continuous Power Dissipation (T = +70NC) A Lead Temperature (soldering, 10s) ................................+300NC Plastic DIP (derate 11.11mW/NC above +70NC) ..........889mW Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = +2.7V to +5.25V COM = 0 f = 2.0MHz external clock (50% duty cycle) 15 clocks/conversion cycle (133ksps) DD SCLK MAX1494.7FF capacitor at VREF pin MAX148external reference, VREF = 2.500V applied to VREF pin T = T to T , unless A MIN MAX otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC ACCURACY (Note 1) Resolution 10 Bits MAX14 A 0.5 Relative Accuracy (Note 2) INL LSB MAX14 B 1.0 Differential Nonlinearity DNL No missing codes over temperature 1 LSB MAX14 A 0.15 1 Offset Error LSB MAX14 B 0.15 2 MAX14 A 1 Gain Error (Note 3) LSB MAX14 B 2 Gain Temperature Coefficient 0.25 ppm/C Channel-to-Channel Offset 0.05 LSB Matching DYNAMIC SPECIFICATIONS (10kHz Sine-Wave Input, 0 to 2.500V , 133ksps, 2.0MHz External Clock, Bipolar Input Mode) P-P Signal-to-Noise + Distortion SINAD 66 dB Noise Total Harmonic Distortion THD Up to the 5th harmonic -70 dB Spurious-Free Dynamic Range SFDR 70 dB Channel-to-Channel Crosstalk 65kHz, 2.500V (Note 4) -75 dB P-P Small-Signal Bandwidth -3dB rolloff 2.25 MHz Full-Power Bandwidth 1.0 MHz CONVERSION RATE 5.5 7.5 Internal clock, SHDN = unconnected 35 65 Internal clock, SHDN = V DD Conversion Time (Note 5) t s CONV External clock = 2MHz, 12 clocks/ 6 conversion Track/Hold Acquisition Time t 1.5 s ACQ Aperture Delay 30 ns Aperture Jitter < 50 ps 2 MAX148/MAX149